Type printing or setting machine



July 3, 1934. M, AMANN T AL 1,964,841

TYPE PRINTING OR SETTING MACHINE Filed May 29, 1933 2 Sheets-Sheet l July 3, 1934. AMANN AL 1,964,841

TYPE PRINTING OR SETTING MACHINE Filed May 29, 1935 2 Sheet's-Sheet 2 Patented July 3, 1934 TYPE PRINTING OR SETTING MACHINE Max Amann and Alfred Lahl, Frankfort-on-the- Main, Germany Application May 29, 1933, Serial No. 673,514 In Germany May 30, 1932 15 Claims.

Type printing or setting machines are known which are equipped with a current impulse transmitting device and a type selecting device. Such machines are joined by a connecting line through which the current impulses are transmitted. These current impulses always actuate the type selecting devices of the machines in reciprocal communication operation, that is to say' when the machines are operable as transmitters or receivers so that, in teletypers for example the text is written in the transmitting machine.

Such printing or setting machines are relative- 1y complicated and therefore expensive, and are in general inefliciently used for reciprocal communication operation. The invention aims at substantially improving the use of such sheet printing or setting machines. According to the invention, devices are provided which make it possible to control the type selecting devices by current impulses produced in the transmitter of the appropriate machine, which impulses are not transmitted over the connecting line.

These devices are, in accordance with the invention, constructed so that communications in one direction take precedence over communication in the other direction.

In this way, it is possible inteletypers for example, to use one and the same machine both as the usual typewriting machine and also as the teletyper, so that although the trafiic between the machines may be quite light, each of the machines can, nevertheless, be fully utilized.

The invention is particularly concerned with sheet printing or setting machines which are motor driven and the motor of which only runs when the machine is in use. In these machines, a switching device has to be provided which switches in the motor when brought into use and which maintains this switching in. independently of the use of the machine. The invention relates to a particular arrangement of this switching device which enables the switching to be carried out both by means within the appropriate machine and by switching steps over the connecting line. In particular, in accordance with the invention, a new construction for a mechanical locking will be described which allows the connection of the motor and of the source of current at the end of the use of the machine to be maintained for a special interval of time and then to be released.

In the drawings, an example of construction of the invention is shown.

Figure 1 shows diagrammatically the construc tion and the connections of two type printers.

Figure 2 shows the circuit arrangement in de--' tail.

Figure 3 illustrates in outline, the construction of a type printer on the start-stop system. 7

Figure 4 shows a time switch for use in the in-, stallation shown in Figure 3 and Figure 5 shows the mechanical inter-connec tion of the starting keys.

In Figures 1 and 2, two type printers Bl are shown which are connected by the line Lg. The printer at each station A, B has devices for actuating exclusively its own type by means of its keyboard without influencing the other printer. The artificial line Kl is, in this case switched in instead of the line Lg. The electromagnetic type selector used makes a sourceof direct current necessary. The current serving for the actuation of the apparatus (stations A and B) is provided by a mains connection device NA on the public supply mains. If the public mains, as is shown in station A, supply alternating current, then the mains connection device must include a rectifier;

The putting into operation of the type printer is effected by depressing a key. The key SchT is for internal use and the key FT for external use. As shown in Figure 5 depression of one key releases the other. Further, two indicating lamps FL and SchL are provided to indicate whether the machine is used for external use or for internal use. Before the circuit arrangement of Figure 2 is described in detail some constructional points of the type printer will be made clear by means of Figures 3 and 4.

The type printer BZ (Figure 3) is driven by a motor M which is supplied from the public mains N when the set of contacts K of a switch device Z are closed. Its speed is maintained constant by means of a contact regulator FZK.

The type printer is provided both with'a receiving device E and with a transmitting device S which are driven by the common motor M according to the direction of the trafiic. The current impulse member of the transmitter or type selecting member of the receiver, asthe case may be, is thus selectively brought into operation for one revolution. During this revolution, the transmitting contacts SK transmit the charac-' teristic current impulses corresponding to the pressure on the key through the line Lg, or the receiving magnet EM, under the influence of the current impulses received through the line Lg, selects a letter to be subsequently printed. Immediately after the beginning of the rotation, the contact JKs of the transmitter or the contact JKe of the receiver, as the case may be (both of which are controlled by a cam), is actuated and remains in the closed position until the end of the rotation.

The above mentioned switching device Z serves not only for starting the motor M, but also for further steps such as switching out the motor at the end of a definite interval of time when no longer required. Its manner of operation is set out in Figure 4.

If a key, for example the key SchT, is depressed for a short time so as to put the type printer BZ into operation, the coil ZMII of the magnet ZM is energized and the armature 28 is attracted. The armature 28 in its normal position is held by the spring 29, and engages with its arm 26' in the groove 25 in the coupling sleeve 11 and holds the coupling 10 closed. The lower end of the armature 28, pivoted on the pin 27, has a projection 30 which bears on the tilting device 33. This tilting device 33 is held by the spring 36 against the stop 35, so that the latch 34 holds the forward end 42 of the lever 3'7 locked in the position shown. The lever 3'7 is rotatable about the pin 38 and has a bend 41 which influences the setting of contacts K, and in fact, in the position shown, holds the contact 44 open. The spring 39 in the normal position of the device tends to swing the lever 3'7 towards the stop 43. When the latch 34 on attraction of the armature 28 swings about the pin 32, the lever 37 is released and snaps upwards under the action of its spring 39 against the stop 43. In this way, the contact 44 and therefore the motor circuit are closed by rapid switching and the motor M is started.

The swinging ofthe tilting device 33 will swing with it the projection 46 on the arm 31. This projection 46 bears against the bend 22 of a Z shaped lever 18, 20, 21 which is pivotally mounted on the pin 19 and is under the influence of a spring 24. The arm 21 of the lever 18 has a projection 17 which is held against the edge of a drum 9 by the action of the spring 24. This drum 9 has a notch 16 in which the projection 1'7 can engage. In the normal position of the switch device, Figure 4, the projection 1'7 is engaged in the notch 16 and holds the drum 9 in a position displaced by 180 relatively to that shown in Figure 4 against the action of the spring 13. In the drawings this effective position of the drum is not shown in order to make the notch 16 visible.

The lever 18 is pivoted against the action of its spring 24 when the armature 28 is attracted and the projection 17 is removed from the notch 16 and the drum 19, under the action of its spring 13, snaps into the position shown in Figure 4 in which its stop 15 lies against a fixed stop 14. At the same time, the arm 20 of the lever 18 moves to the right so that its free end 23, which lies in the groove 5 displaces the sleeve 3 towards the right. The sleeve 3 has on the left, a cam 4 whi'cl'i'can act on the projection 40 of the lever 3'7, only when it is in the extreme left hand position.

The levers 3'7 and 18 remain moreover, for the time being, in the working position when the armature 28 of the magnet ZM is again released, because the projection 1'7 of the lever 18 slides over the smooth edge of the drum 9, and the lever 18 remains in the pivoted position under the action of the spring 24 and in that position the cam 4 on the shaft 6 cannot act on the lever 3'7.

The motor M, once started by the contact 44, runs until the projection 17 engages in the notch 16.

The motor M drives a relatively quickly running shaft 6 through a worm gear 1 and a very slowly running shaft 8 through a second worm gear 2. The shaft 6 rotates the sleeve 3 and the cam 4 by means of a pin '7. The shaft 8 drives the sleeve 11 by means of a pin 12 which carries with it the drum 9 by means of the coupling teeth 10 so long as the magnet ZM is not energized. The drum 9 is mounted to rotate on the shaft 8 but is not axially movable. It has a normal position determined by the spiral spring 13 and the stop 14 into which it snaps back when, on attraction of the armature 28, the toothed coupling 10 is released by the movement of the sleeve.

The drum 9 is, for example, rotated through half a revolution by the shaft 8 and the pin 12 and the coupling 10 of the sleeve 11. This, by suitable design of the gearing 1 and 2 takes about 1 minute. The projection 1'7 then snaps into the notch 16 under the action of the spring 24. The arm 20 of the lever 18 thus swings in the direction of the arrow and in this Way brings the cam 4 over the projection 40 so that after, at the most, one revolution of the relatively fast running shaft 6, the lever 37 is depressed and the motor switch contact 441s opened by means of the projection 41 and the motor M is stopped. The remaining contacts of the set of spring contacts K are also actuated and cause further switching steps which will be described below. The forward end 42 of the lever 37 also snaps past the latch 34 and is thus latched again in the position shown in Figure 4. The arrangement is thus ready to be operated once more.

When the magnet ZM is again energized through its windings I and II, the sleeve 11 is again axially displaced by the arm 26 of the armature 28 and the coupling 10 is released. The drum 9 then snaps back into the position shown in Figure 4. A slow rotation of the drum 9 for the starting of the motor by the time switching device is then initiated so that the motor is stopped about 1 minute after the last energization of the magnet ZM which always takes place when asignal is transmitted or received.

The connection between the switch device Z and the type printers is shown in Figure 2.

The case in which the station A is set'solely with internal use will first be considered, that is to say the case in which the printer only prints signals tapped out on its own keyboard. If its apparatus Bl is at rest, in which case both lamps Fl and SchL are out, and the starting key SchT is actuated for a short time, for the internal use the following circuit will be closed: (Figure 2) winding III of relay U, key SchT, winding II of magnet ZM of the switch Z,

The relay U and the magnet ZM respond approximately at the same time.

The magnet ZM of the time switch Z (see Figures 2 and 4) brings the set of contacts K into the working position. This closes the motor circuit at 44, short circuits the winding ZMI of the magnet ZM through a make and break contact, and, through a double make contact which is at negative potential, prepares the circuit for the type selecting-receiving electromagnet EM and the transmitting key SK. This circuit is closed through the artificial line KL by means of the contacts 103 and a4. The relay U switches in the artificial line KL on response of its contacts u1u4, that is to say, on switching out the line Lg to the station B, switches preparatorily the differential winding UI by means of the contact ul across the wires a, b of the line Lg and finally closes the following circuit including the holding winding II of the relay U:

11.2, winding II of relay U, lamp SchL, normal contact of the key FT, double make contact of K,

The relay U thus remains energized. At the same time, the indicating lamp SchL lights up in its own station A.

During the off-period of the switch Z which lasts about 1 minute during which the preparatory steps necessary for the printing, such as insertion of the sheets or the like, can be undertaken, the transmission must be begun. By depression of a key of the keyboard 3 (Figure 3) the transmitting contacts Sic are actuated (Figures 2 and 3), and at the same time the cam contact J Ks is closed. The transmitting contacts influence the magnet EM so that a letter is selected, in a manner which need not be described in greater detail, and is printed. In this way, the cam contact JKe is also closed. During the closing of the contact JKe or JKs. the following circuit for the magnet ZM is closed:

JKs or JKc, resistance R2, winding II of magnet ZM,

Whenever a signal is printed due to energization of the magnet ZM, the notched drum 9 (Figure 4) of the switch Z always snaps back so that from then on, the switched off period of 1 minute again starts to run.

Owing to the short circuiting of the winding ZMI of the magnet ZM, the release of its armature will be delayed so that on the occurrence of a rapid sequence of signals, the armature 28 remains attracted and the coupling 16 disengaged so that the teeth of the coupling 10 are effectively spared.

The motor M is so constructed that it can be connected to alternating current or to direct current mains. Its speed, with alternating current, is regulated by the resistance R1 connected in parallel. With direct current, as in the case of station B, the contact FlK is connected in series, and the resistance R1 and condenser C3 in parallel.

The same alternating or direct current mains N supply the direct current operating voltage B8,!) to a mains connection device NA for actuating the selecting and indicating steps. The mains conl nection device for alternating current mains (station A) consists of an autotransformer SpTr, a full wave rectifier Gl, a bad-pass filter and smoother Cl, Dr, G2; with direct current main, (station B) the required voltage is obtained from the potentiomenter Pot, and the current passes to the motor connections through iron hydrogen resistances EW.

When typewriting is ended, the type printer Bl, after the switched off period of 1 minute, is

' stopped. In this way, the set of spring contacts K is mechanically returned and latched and the negative potential is destroyed by the double make contact, the holding circuit through the winding II for the relay U is interrupted, the lamp SchL is extinguished and the motor is stopped. The arrangement again assumes the shown position, that is to say, the contacts c3 and c4 are closed on the connecting line Lg and the contact :12 prepares the circuit of the lamps Fl; further, the winding UI no longer bridges the line Lg.

At this instant, the line Lg is merely at the positive potential determined by the magnet EM and the transmitter Sic. There is thus no flow of current, with the exception of the small internal no-load consumption of the mains connection device NA.

It is only when the station A is connected for remote printing and functions as a teletyper that there is any switching in of one or both mains connection devices so that the printers work in the so called closed circuit connection.

By depressing the key FT at the station A for setting the arrangement for reciprocal communication with the printer Bl of the station B, the following circuit is closed:

marking contact of key FT, resistance R2, winding 11 of magnet ZM,

The magnet ZM then responds and actuates the set of contacts K so that the motor M in the station A is switched in and the circuit for the lamp Fl is closed through the double make contact K and the resistance R3. The relay U is not energized.

While the wire a of the line Lg, permanently inoperative, is at a positive potential owing to the contact a3, magnet EM and the transmitting contact SK, the wire 1) is however, at a negative potential owing to the double make contact of the actuated set of contacts K and the short circuit contact for the winding ZMI of the magnet ZM. In the station B, in which there is no short circuit for the winding ZMI of the magnet ZM, the magnet in this circuit created in the line Lg will thus be energized. Therefore, by releasing the switch Z, the motor M is started, the lamp FL lit, and due to the short circuit of the winding ZMI of the magnet ZM, there will immediately be a voltage in the line Lg. The magnets EM, as is obvious, are connected in series with the sources of current BS1) of the two stations Aand B.

The artificial lines KL are so designed that the attracting force and the time constant of the magnets EM for internal use, that is to say when working with the single voltage, are approximately the same as for the external use with series con nection of the sources of current.

In external use, the contacts JKs and JKe in the station A are closed at each transmission of a signal but in the station B, only the contact JKc is actuated. Thus, in the two printers, the magnets ZM are always therefore again energized so that the switch Z finally becomes inoperative only after about 1 minute after the transmission of the last signal from the station A.

Similar circumstances arise when the station B is the transmitting station.

A station connected through the line Lg for external use has the preference compared with the internal use of the other station that it is ca- 130 pable of breaking its typewriting action in favor of its teletyping. Naturally, indicating signals are provided for this breaking in at the receiving sta-. tion. A change in the signals SchL and Fl of the distant. printer is sufiicient for this purpose. By 135 means of these indicating signals, the sheet, in sheet printers, can then be changed or, in the receiving station, by means of a change of signals, the type roller is shifted by hand or controlled by the line Lg for the reception of the distant communication to which preference has been given. The latter happens, for example, when in the station introducing the external use the line shift key on the keyboard is depressed several times after the starting.

Let it be assumed that a printed communication is to be given in the station A set for internal use; by means of the station B. On the depression of the key FT therein, as described, a starting difference of potential is given to the terminals 150 a, b of the line Lg. This affects however, not the winding I of the magnet ZM as in-the inoperative condition of the station A, but the winding I of the relay U which bridges therein the terminals a, b of the line Lg through the contact ul. This winding is connected to work mutually with the holding winding II of the relay U and by its energization releases the relay U in the station A.

The returning of the contacts 103 and 114 results in the disconnection of the artificial line KL necessary for internal use and connects the receiving magnet EM of the station A in series with the already connected receiving magnet EM of the station B. The contact 1L2 finally disconnects the relay U and lights up the lamp FL instead of the lamp SchL. This change in the indicating signals is a signal for the station A to change the just printed sheet and to await the printed communication from the station B. When station B has finished its communication, the lamp FL goes out at the end of the switching out period, so that after a new starting of its machine by depression of its key SchT and return of its sheet the previously started writing can be completed. The keys SchT and FT of the stations A and B are mechanically connected together, in the manner in dicated in Figure 5, in order to avoid trouble which, for example, might occur should both keys be simultaneously depressed.

The example described with reference to the drawings shows a system with, for the greater part, similarly built and operated machines. The type printing and setting machine in accordance with the invention is not restricted to use in such systems. It can also be used in a system with a multiplicityof machines of different types connected by lines, which make possible external or internal communication operation in fixed or selectable switching sequences. Also, the number of wires in the connecting line is immaterial.

It is essential for the invention that by the use of uniform additional parts (ZM, KL) the type printing or setting machines are made usable for various purposes, so that communications in a particular direction take preference'over internal communications. 1

We claim:-

1. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a transmitting device connected to said line circuit, a type selecting device, a common motor for driving said transmitting device and said type selecting device, means connected to said terminals for controlling the type selecting device by current impulses of code signals, and switch means adapted to disconnect the circuit of said type selecting device and the circuit of said current impulse transmitting device from the said terminals and to connect this type selecting device in a circuit associated solely with the transmitting device of the same machine.

2. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a transmitting device connected to said terminals, a type selecting device, a common motor for driving said transmitting device and said type selecting device, means connected to said terminals for controlling the type selecting device by current impulses of code signals, switch means adapted to disconnect the circuit of said type selecting device and the circuit of said current impulse transmitting device from the said terminals and to connect this type selecting device in a circuit associated solely'with the transmitting device of the same machine, anddevices adapted to-release each other on actuation for actuating said switch means for selectively connecting the machine so as to be influenced either only by the current impulses produced by its own transmitter or in addition by those produced by the transmitter of a distant machine.

3. A type printing or setting machine, com-' prising in combination, terminals of a connecting line circuit, a transmitting device connected to said terminals, a type selecting device, a common motor for driving said transmitting device and said type selecting device, means connected to said terminals for controlling the type selecting device by current impulses of code signals, switch means adapted to disconnect the circuit of said type selecting device and the circuit of said current impulse transmitting device from said terminals and to connect this type selecting device in a circuit associated only with the transmiting device of the same machine, devices adapted to release each other on actuation for actuating the switch means for selectively connecting the machine so as to be influenced either only by current impulses produced by its owntransmitter or in addition by those produced by the transmitter of a distant machine, and warning devices for the different indications of the connection of the machine in reciprocal and in single communication operation.

4. A telegraph communication system comprising a connecting line, a plurality of type printing machines each including a current impulse transmitting device connected to said connecting line, a type selecting device, means connected to said connecting line for controlling said type selecting device by means of current impulses of code signals, a source of current connected with said transmitting device and with said controlling means and said connecting line; said source of current of each of said machines being connected in series over the said connecting line for reciprocal communication operation of the machines, at least one of which machines further comprises switching means adapted to discon meet the circuit of said current impulse transmitting device, the source of current and the circuit of said type selecting device from said connecting line and to connect this type selecting device in a circuit associated only with the transmiting device and the source of current of the same machine.

5. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a transmitting device connected to said terminals, a type selecting device, means connected to said terminals for controlling the type selection device by means of current impulses of code signals, a source of current, switch means adapted to close a circuit including said means for controlling said type selecting device, said current impulse transmitting device, an artificial line and the appropriate source of current or a circuit including said means for controlling said type selecting device, said current transmitting device, the appropriate source of current and said terminals in order in reciprocal communication operation to supply the means for controlling said type selecting device from the source of current connected in series with the second machine.

6. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a type selecting device, means connected with said terminals for controlling the type selection by means of current impulses of code signals, a current impulse transmitting device connected to the said terminals, switching means adapted to disconnect the circuit of said type selecting device and said current impulse transmitting device from said terminals and adapted to connect the type selecting device in a circuit associated solely with the impulse. transmitting device of the same machine and switch means connected to said terminals adapted on actuation by switching steps upon the connecting line to be influenced so as to establish the connection of said controlling means to the connecting line by releasing said first named switch means. a

7. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a type selecting device, means connected to said terminals for controlling said type selecting device by means of current impulses of code signals, a current impulse transmitting device connected to said terminals, a source of current, a switch device adapted on actuation to disconnect said transmitting device and said means for controlling said type selecting device from said terminals and for connecting said controlling means in a circuit including only said transmitting device, an artificial line and the source of current, which switch device is further adapted, on actuation by switching steps on the connecting line, to be influenced so as to connect said means for controlling said type selecting device to said terminals.

8. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a type selecting device, means connected to said terminals for controlling said type selecting device by means of current impulses of code signals, a source of current, a switch device with a plurality of mutually set energizing windings, said switch device being adapted, on actuation by a winding to disconnect said means for controlling said type selecting device from said terminals and to switch in an artificial line and the source of current in a circuit including said transmitting device and to connect the other winding to said terminals, said switch device being further adapted, on actuation, by the winding connected to said terminals, to connect said means for controlling said type selecting device to said terminals.

9. A type printing or setting machine, comprising in combination, connecting terminals of a connecting line circuit, a type selecting device, means connected to the said terminals, for controlling said type selecting device by means of current impulses of code signals, a current impulse transmitting device connected to said terminals, a source of current, a motor driving, when actuated, said type selecting device for one rotation, switch means for selectively disconnecting said means for controlling said type selecting device from the connecting line, a switch device, an actuating member for controlling said switch device, and means for connecting said switch device to said terminals so that said switch device is adapted to be influenced both by switching steps on the connecting line and by said actuating member and to connect the motor on being influenced.

10. A type printing or setting machine, comprising in combination, the terminals of a connecting line circuit, a type selecting device, means connected to said terminals for controlling said.

type selecting device by means of current impulses of code signals, a current impulse transmitting device connected to said terminals, a source of current, a motor driving said type selecting device and said transmitting device on actuation for one rotation, switch means for selectively disconnecting said means for controlling said type selecting device from the connecting line, a switch device forconnecting the motor, an electromagnet for controlling said switch device, provided with two windings, one of which windings is connected to said terminals and keys for closing circuits through the other of said windings.

11. A type printing or setting machine, comprising in combination, the terminals of a connecting line circuit, a type selecting device, means connected to said terminals, for controlling said type selecting device by means of current impulses oi code signals, a current impulse sending device connected to said terminals, a source of current, a motor driving said type selecting device and said transmitting device on actuation for one revolution, switch means for selectively disconnecting said means for controlling said type selecting device from the connecting line, a switch device controlling contacts for switching in said motor, an electromagnet for controlling said switch device and provided with two windings, one of which windings is connected to said terminals and is adapted to be short circuited by contacts of said switch devices and keys for closing circuits for the other of said windings.

12. A type printing or setting machine, comprising in combination, the terminals of a connecting line circuit, a type selecting device and means connected to said terminals for controlling said type selecting device by means of current impulses of code signals, a, current impulse transmitting device connected to said terminals, a source of current, a motor driving said type selecting device and said transmitting device on actuation for one revolution, switch means for selectively disconnecting said means for controlling said type selecting device from the connecting line, a switch device controlling contacts for switching in said motor and for connecting said source of current with said terminals, an electromagnet for controlling said switch device and provided with two windings, one of which windings is connected to said terminals and is adapted to be short circuited by contacts of the said switch device and keys for closing circuits for the other of said windings.

13. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a type selecting device, means connected to said terminals for controlling said type selecting device at will by means of current impulses of code signals, a current impulse transmitting device connected to the said terminals, a source of current, switch means for selectively disconnecting said terminals from said means for controlling said type selecting device, a motor for driving said type selecting device, a switch device controlling contacts for switching in said motor, an electromagnet for controlling said switch device adapted to be influenced by switching steps in the connecting line, keys for influencing said electromagnet, contacts controlled by said type selecting device and by said transmitting device for influencing said electromagnet and a further switch for controlling said switch device at the end of the influencing of said electromagnet.

14. A type printing or setting machine, comprising in combination, terminals of a connecting line circuit, a type selecting device, means connected to said terminals for controlling said type selecting device at will by means of current impulses of code signals, a current impulse transmitting device connected to said terminals, a source of current, switch means for selectively disconnecting said terminals from said means for controlling said type selecting device, a motor for driving said type selecting and transmitting device, a switch device comprising a mechanically latched set of contacts comprising contacts for switching insaid motor, an electromagnet adapted to be influenced by switching steps in the connecting line and by switching steps of the 'machine and adapted to unlatch said set of contacts on being restored, a fast running pinion driven by said motor controlling said means -for returning and latching said set of contacts, a slow running pinion driven by said motor controlling on deenergization of said electromagnet means which influence the returning means of said fast running pinion.

15. A type printing or setting machine, comprising in combination, terminals of 2. connecting line circuit, a type selecting device, means connected tosaid terminals for controlling said type selecting device at will by means of current impulses of code signals, a current impulse transmitting device connected to said terminals, a source of current comprising a device for obtaining direct current from public mains, switch means to close a'circuit including said means for controlling said type selecting device, said current impulse transmitting device and the appropriate source of current or for closing a circuit including said means for controlling said type selecting device, said current impulse transmitting device, the source of current and said terminals in order, in reciprocal communication of the second machine, to supply the means for controlling said type selecting device from the source of current connected in series of the second machine.

MAX AMANN. ALFRED LAHL. 

